Memorandum

Design Departure / EDD Application Form (with example)

Standards & Guidelines

Road Design

Applies to departures from:

· Austroads Guide to Road Design

· DIT Road Design Supplements

· Road Design Master Specification

· at the discretion of the Principal Road Design Engineer

K Net Number: 10322417

Document Revision: 4

Document Date: 03/11/20

Document Amendment Record

Rev

Change Description

Date

Author

Checked

Authorised

1

Initial Issue

18/08/18

J Davies

E Winkler

A Glavinic

2

Safety strategy – sign-off removed

13/05/19

J Davies

E Winkler

A Glavinic

3

‘Certification by designer’ box & minor corrections

24/06/20

E Winkler

J Davies

J Davies

4

Minor corrections & updated section A

03/11/20

J Davies

M Mak

J Davies

Document Management

This document is the Property of the Department of Planning Transport and Infrastructure (DPTI) and contains information that is confidential to DPTI. It must not be copied or reproduced in any way without the written consent of DPTI. This is a controlled document and it will be updated and reissued as approved changes are made.

To be read in conjunction with DPTI Design Departure / EDD Procedure:

Location

Document Ref

Internal

Knet# 12971461

External

https://www.dpti.sa.gov.au/standards/road_design_outputs

Contents

Contents3

Design Departure (DD) and/or Extended Design Domain (EDD) Application Form4

Design Departure (DD) and/or Extended Design Domain (EDD) Application Form - EXAMPLE9

Design Departure (DD) and/or Extended Design Domain (EDD) Application Form

KNET FILE NO:

#

PROJECT:

PROJECT NAME

LOCATION:

Identify the location of the proposal, e.g. street name(s), area, suburb/town

PROPOSED BY:

Name:

Date:

Position:

General principles

The documentation and process of seeking and obtaining endorsement and approvals remains the responsibility of the proposer.

This process for completion of this form is outlined in the “Design Departure / EDD Form Procedure”, refer kNet# 12971461

To be read in conjunction with DPTI Brownfield / Greenfield Guideline Knet# 12986288

This application form is to be used to ensure that all reasonable steps have been undertaken to achieve Normal Design Domain (NDD) prior to the consideration of Extended Design Domain (EDD). NDD criteria should be applied where possible. If site constraints restrict the upgrade of the existing geometric alignment with normal design domain standards, and acceptable operational and safety levels can be maintained, the use of EDD can be considered as part of the upgrade works. The use of EDD is limited to only one design element and must be accompanied with an off-set element designed above minimum NDD. This form provides technical approval of the design only. Final approval of installation/construction of design remains with the Project Manager/Sponsor. This form can be applied to NDD and other non-standard applications where applicable.

EDD is only applicable if any of the following apply:

· There are significant controls/constraints on the site.

· Significant investment would be required to ameliorate the constraint and it is unjustifiable in the scope of works.

· The existing facility is likely to have been designed to a lesser standard.

· There is no accident/crash history or operational problems associated with the site, relating to the EDD parameter under consideration.

Information provided in support of this EDD should, where possible, limit the use of jargon and be in plain English.

Extended Design Domain must be applied at the scoping stage only.

Applies to departures from:

· Austroads Guide to Road Design

· DIT Road Design Supplements

· Road Design Master Specification

· at the discretion of the Principal Road Design Engineer

Certification by designer

By submitting this form the designer certifies that, while this design departure has been submitted for Departmental approval, they are satisfied that the design meets safety standards and requirements. Certification by the designer also acknowledges that where the element falls outside of normal design domain, their engineering judgement has been used in the design process.

NAME

POSITION (& COMPANY)

DATE

CONSULTATION WITHIN DIT (add any relevant discipline as necessary)

Discipline

Reviewer

Comments

Date

Road & Marine Assets

Traffic Operations

Technical Services

DIT PROJECT MANAGER COMMENTS

Any further considerations that should be considered when reviewing and/or approving the proposed use of EDD.

CERTIFICATION

In compliance with reasonable engineering principles, I consider the technical mitigating treatments appropriate and the decision to adopt this EDD as acceptable, subject to any conditions below.

Name

PRINCIPAL ROAD DESIGN ADVISOR

Signature

Date:

**Following approval, a copy of this form and supporting documentation, must be forwarded to the Director, Technical Services, DPTI.**

TECHNICAL SERVICES APPROVAL

I approve the use of the mitigating treatments for this EDD in this project as detailed, subject to any conditions outlined below.

I reject the use of the mitigating treatments and request further consideration.

I endorse

Name:

DIRECTOR, TECHNICAL SERVICES

Signature:

Date:

FINAL APPROVAL (IF REQUIRED)

– IF THE PRINCIPAL LEADS DO NOT COME TO AN AGREEMENT

I approve

I reject

Name:

CHIEF ENGINEER

Signature:

Date:

Design Departure (DD) and/or Extended Design Domain (EDD) Application Form

(This section can be expanded to multiple pages to cover any discussions involved and attachments required.)

FOR EDD ALL SECTIONS SHOULD BE COMPLETED

SECTION A

DESIGN

PROJECT BACKGROUND AND SCOPE

Provide details of the scope of the project, the purpose of the design and the project site.

DETAIL THE PROJECT PROBLEM AND WHY DD or EDD IS BEING CONSIDERED.

Provide all relevant information on the project problem. Include details of the issue/s, data available, design criteria, crash statistics, cross sections, site constraints, speed, composition of traffic, traffic volumes, etc.

DATA AND STATISTICS

Provide all available data including crash statistics, speed, composition of traffic traffic volumes, etc. The crash data is particularly important as no accident/crash history is a criteria for the use of DD/EDD.

CLEARLY ARTICULATE IN DETAIL OPTIONS CONSIDERED TO ADDRESS THE PROBLEM.

Description of what is proposed. For EDD need to include both NDD and EDD options that were considered.

SECTION B

RISK ASSESSMENT

THIS ASSESSMENT MUST BE DONE IN ACCORDANCE WITH DPTI RISK MANAGEMENT POLICY DP086.

DISCUSS THE IMPACT AND FEASIBILITY ON THE PROJECT OUTCOME OF THE OPTIONS IDENTIFIED IN ABOVE.

Cost & Time;Social, Environmental, Safety & Traffic; Maintenance. Use tables, charts, and drawings as appropriate to illustrate and clarify impacts. Document the risk assessment and apply mitigation mearsures and provide a risk rating (low, medium, high)

CLEARLY ARTICULATE IN DETAIL THE MITIGATION MEASURES TO ADDRESS THE PROBLEM WHEN APPLYING EDD.

Plain english description of what is proposed to address EDD. Describe (any) alternatives that were considered - were these based NDD values?

WHERE RISKS ARE IDENTIFIED AS EXTREME OR HIGH, A FORMAL DETAILED RISK ASSESSMENT SHALL BE UNDERTAKEN

SECTION C

MONITORING

DETAIL PROPOSED MONITORING REGIME FOR THE DESIGN, POST CONSTRUCTION

To be provided only if deemed necessary by Principal Road Advisor. Should include Monitoring regime, Maintenance.

SECTION D

MISC.

OTHER RELEVANT INFORMATION

Description

**ATTACH RELEVANT PLANS, MAPS, PHOTOS, DRAWINGS**

Design Departure / EDD Application Form (with example)Design Departure (DD) and/or Extended Design Domain (EDD) Application Form - EXAMPLE

Master SpecificationRevision A15

Design Departure (DD) and/or Extended Design Domain (EDD) Application Form - EXAMPLE

DESIGN DEPARTURE

EDD

KNET FILE NO:

#1122Ɛ34567

PROJECT:

Honeysville Upgrade Project

LOCATION:

Horizontal Alignment; Flanders Grove Extension

PROPOSED BY:

Name: A Dogsbodie

Date: 31 April 2017

EXAMPLE

Position: Departmental Project Representative

General principles

The documentation and process of seeking and obtaining endorsement and approvals remains the responsibility of the proposer.

This process for completion of this form is outlined in the “Design Departure / EDD Form Procedure”, refer kNet# 12971461

To be read in conjunction with DPTI Brownfield / Greenfield Guideline Knet# 12986288

This application form is to be used to ensure that all reasonable steps have been undertaken to achieve Normal Design Domain (NDD) prior to the consideration of Extended Design Domain (EDD). NDD criteria should be applied where possible. If site constraints restrict the upgrade of the existing geometric alignment with normal design domain standards, and acceptable operational and safety levels can be maintained, the use of EDD can be considered as part of the upgrade works. The use of EDD is limited to only one design element and must be accompanied with an off-set element designed above minimum NDD. This form provides technical approval of the design only. Final approval of installation/construction of design remains with the Project Manager/Sponsor. This form can be applied to NDD and other non-standard applications where applicable.

EDD is only applicable if any of the following apply:

· There are significant controls/constraints on the site.

· Significant investment would be required to ameliorate the constraint and it is unjustifiable in the scope of works.

· The existing facility is likely to have been designed to a lesser standard.

· There is no accident/crash history or operational problems associated with the site, relating to the EDD parameter under consideration.

Information provided in support of this EDD should, where possible, limit the use of jargon and be in plain English.

Extended Design Domain must be applied at the scoping stage only.

CONSULTATION

Discipline

Reviewer

Comments

Date

Road & Marine Assets

Carrie Oakey

No Objections from Asset Management.

23/05/2017

Field Services

April Shauer

Not applicable

N/A

Traffic Operations

Robin Banks

No objections

30/05/2017

Safety Strategy

Willie Everlearn

No objections

EXAMPLE

09/05/2017

Technical Services

Sue Purglew

As the EDD Element is related to road geometry, Project Technical Services has been consulted. General agreement with minor condition.

21/06/2017

PROJECT MANAGER COMMENTS

Any further considerations that should be considered when reviewing and/or approving the proposed use of EDD.

No further comments. The use of the EDD for this design element is supported when the operating speed of the road user is considered.

CERTIFICATION OF DESIGN DEPARTURE

I consider the technical mitigating treatments appropriate and compliant with reasonable engineering principles, and the decision to adopt this Design Departure/EDD is acceptable, subject to any conditions below.

Name Max Power

PRINCIPAL ROAD DESIGN ADVISOR

Signature Max Power

Date: 24/06/2017

**Following approval, a copy of this form and supporting documentation, must be forwarded to the Manager Technical Services, DPTI. If the change is considered controversial or politically sensitive in nature, this should be noted to ensure form is elevated to CoH or delegate level**

TECHNICAL APPROVAL OF EDD

I approve the use of the mitigating treatments for this EDD in this project as detailed, subject to any conditions outlined below.

I reject the use of the mitigating treatments and request further consideration.

I endorse

Name: Russell Leeves

MANAGER, TECHNICAL SERVICES

Signature: R. Leeves

Date: 27/06/2017

APPROVAL (IF DEEMED NECESSARY)

I approve

I reject

Name: Warren Peace

COMMISSIONER OF HIGHWAYS / DELEGATE

Signature: Warren Peace

Date: 8/07/2017

Design Departure (DD) and/or Extended Design Domain (EDD) Application Form - EXAMPLE

EXAMPLE

(This section can be expanded to multiple pages to cover any discussions involved and attachments required.)

FOR EDD ALL SECTIONS SHOULD BE COMPLETED

SECTION A

DESIGN

DETAIL THE PROJECT PROBLEM AND WHY DD or EDD IS BEING CONSIDERED.

The Flanders Drive extension provides a link from the Flanders Medical Centre to Starling Road. Due to the constraints from the location of existing intersections, existing buildings and car parking facilities and the need to consider the future extension of the RaiLink line the horizontal radius of Flanders Drive extension is required to be reduced from the Normal Design Domain, the proposed alignment is shown in Figure 1.

EXAMPLE

Figure 1: Proposed 132.5m horizontal radius with adverse crossfall

CLEARLY ARTICULATE IN DETAIL OPTIONS CONSIDERED TO ADDRESS THE PROBLEM.

The following options have been considered;

1. Provide a 200m horizontal curve with adverse crossfall (NDD).

1. Change the road crossfall so that the curve is super-elevated (NDD).

1. Provide a 90m or greater horizontal curve (EDD).

SECTION B

RISK ASSESSMENT

THIS ASSESSMENT MUST BE DONE IN ACCORDANCE WITH DPTI RISK MANAGEMENT POLICY DP086.

DISCUSS THE IMPACT AND FEASIBILITY ON THE PROJECT OUTCOME OF THE OPTIONS IDENTIFIED IN ABOVE.

Option 1. Changing the horizontal alignment to achieve a 200m radius (see Figure 2 below).

In order to achieve a horizontal alignment with a 200m radius the road alignment would be required to be shifted further West (circa 5-10m). This is however considered undesirable as;

· It reduces the available development space to the West and increases the ‘dead’ space to the south of the corridor.

· It increases the interface of the potential rail alignment with the road alignment. The below sketch shows the likely interface between Flanders Drive Extension and the RaiLink alignment based on the 15% concept design.

In Figure 2 the 200m horizontal design is indicated in green, the red lines show how the Northern shared path would be required to be realigned. The magenta lines show the required stopping sight distance and safe intersection sight distance associated with the greater 200 radius, this is undesirable as it further restricts the sight line due to the likely pier locations for RaiLink.

EXAMPLE

Potential RaiLink Alignment

Safe Intersection Sight Distance

Stopping Sight Distance

Figure 2: 200m horizontal radius curve overlay

Option 2. Change the road crossfall so that the curve is super-elevated.

Altering the crossfall to produce a super elevated curve leads to an increased extent of works on Other Drive and Another Avenue including, changes to drainage patterns and property access arrangements. Consequently, increasing disruption for stakeholders and project costs.

Option 3. Provide a 90m or greater horizontal curve on adverse crossfall (EDD);

A horizontal radius of 132.5m on adverse crossfall can be achieved and is considered the most optimal design achievable whilst providing;

· An appropriate integration of the Flanders Drive Extension and the future RaiLink

· Good use of the available land and minimises wasted verge space

CLEARLY ARTICULATE IN DETAIL THE MITIGATION MEASURES TO ADDRESS THE PROBLEM WHEN APPLYING EDD.

EXAMPLE

Flanders Drive Extension has been designed to a design speed of 60km/h (posted 50km/h). The use of Normal design domain criteria requires a horizontal curve of 200m radius for adverse crossfall at 60km/h design speed. Under extended design domain the horizontal radius may be reduced to 90m (Austroads Part 3 table 7.10).

The close proximity of signals at each end of the Flanders Drive Extension will keep the operating speed of traffic at or below 50km/h within this area.

A horizontal curve has been designed with an optimal 132.5m radius, which is suitable for an operating speed of 50km/h using Normal Design Domain and is also greater than the Extended Design Domain value for a 60km/h design speed, as per Austroads table 7.10

(EDD)

(NDD)

WHERE RISKS ARE IDENTIFIED AS EXTREME OR HIGH, A FORMAL DETAILED RISK ASSESSMENT SHALL BE UNDERTAKEN

SECTION C

MONITORING

DETAIL PROPOSED MONITORING REGIME FOR THE DESIGN, POST CONSTRUCTION

None

SECTION D

MISC.

OTHER RELEVANT INFORMATION

None

**ATTACH RELEVANT PLANS, MAPS, PHOTOS, DRAWINGS**

EXAMPLE